git.sesse.net Git - nageru/blob - midi_mapper.cpp

   1 #include "midi_mapper.h"
   2 #include "midi_mapping.pb.h"
   3
   4 #include <alsa/asoundlib.h>
   5 #include <google/protobuf/text_format.h>
   6 #include <google/protobuf/io/zero_copy_stream.h>
   7 #include <google/protobuf/io/zero_copy_stream_impl.h>
   8 #include <fcntl.h>
   9 #include <sys/eventfd.h>
  10
  11 #include <functional>
  12 #include <thread>
  13
  14 using namespace google::protobuf;
  15 using namespace std;
  16 using namespace std::placeholders;
  17
  18 namespace {
  19
  20 double map_controller_to_float(int val)
  21 {
  22         // Slightly hackish mapping so that we can represent exactly 0.0, 0.5 and 1.0.
  23         if (val <= 0) {
  24                 return 0.0;
  25         } else if (val >= 127) {
  26                 return 1.0;
  27         } else {
  28                 return (val + 0.5) / 127.0;
  29         }
  30 }
  31
  32 }  // namespace
  33
  34 MIDIMapper::MIDIMapper(ControllerReceiver *receiver)
  35         : receiver(receiver), mapping_proto(new MIDIMappingProto)
  36 {
  37         should_quit_fd = eventfd(/*initval=*/0, /*flags=*/0);
  38         assert(should_quit_fd != -1);
  39 }
  40
  41 MIDIMapper::~MIDIMapper()
  42 {
  43         should_quit = true;
  44         const uint64_t one = 1;
  45         write(should_quit_fd, &one, sizeof(one));
  46         midi_thread.join();
  47         close(should_quit_fd);
  48 }
  49
  50 bool load_midi_mapping_from_file(const string &filename, MIDIMappingProto *new_mapping)
  51 {
  52         // Read and parse the protobuf from disk.
  53         int fd = open(filename.c_str(), O_RDONLY);
  54         if (fd == -1) {
  55                 perror(filename.c_str());
  56                 return false;
  57         }
  58         io::FileInputStream input(fd);  // Takes ownership of fd.
  59         if (!TextFormat::Parse(&input, new_mapping)) {
  60                 input.Close();
  61                 return false;
  62         }
  63         input.Close();
  64         return true;
  65 }
  66
  67 void MIDIMapper::set_midi_mapping(const MIDIMappingProto &new_mapping)
  68 {
  69         if (mapping_proto) {
  70                 mapping_proto->CopyFrom(new_mapping);
  71         } else {
  72                 mapping_proto.reset(new MIDIMappingProto(new_mapping));
  73         }
  74
  75         num_controller_banks = min(max(mapping_proto->num_controller_banks(), 1), 5);
  76         current_controller_bank = 0;
  77 }
  78
  79 void MIDIMapper::start_thread()
  80 {
  81         midi_thread = thread(&MIDIMapper::thread_func, this);
  82 }
  83
  84 #define RETURN_ON_ERROR(msg, expr) do {                            \
  85         int err = (expr);                                          \
  86         if (err < 0) {                                             \
  87                 fprintf(stderr, msg ": %s\n", snd_strerror(err));  \
  88                 return;                                            \
  89         }                                                          \
  90 } while (false)
  91
  92
  93 void MIDIMapper::thread_func()
  94 {
  95         // TODO: Listen on any port, instead of hardcoding 24:0.
  96         snd_seq_t *seq;
  97         int err;
  98
  99         RETURN_ON_ERROR("snd_seq_open", snd_seq_open(&seq, "default", SND_SEQ_OPEN_DUPLEX, 0));
 100         RETURN_ON_ERROR("snd_seq_nonblock", snd_seq_nonblock(seq, 1));
 101         RETURN_ON_ERROR("snd_seq_client_name", snd_seq_set_client_name(seq, "nageru"));
 102         RETURN_ON_ERROR("snd_seq_create_simple_port",
 103                 snd_seq_create_simple_port(seq, "nageru",
 104                         SND_SEQ_PORT_CAP_WRITE |
 105                         SND_SEQ_PORT_CAP_SUBS_WRITE,
 106                         SND_SEQ_PORT_TYPE_MIDI_GENERIC |
 107                         SND_SEQ_PORT_TYPE_APPLICATION));
 108
 109         snd_seq_addr_t addr;
 110         RETURN_ON_ERROR("snd_seq_parse_address", snd_seq_parse_address(seq, &addr, "24:0"));
 111         RETURN_ON_ERROR("snd_seq_connect_from", snd_seq_connect_from(seq, 0, addr.client, addr.port));
 112
 113         int num_alsa_fds = snd_seq_poll_descriptors_count(seq, POLLIN);
 114         unique_ptr<pollfd[]> fds(new pollfd[num_alsa_fds + 1]);
 115
 116         while (!should_quit) {
 117                 snd_seq_poll_descriptors(seq, fds.get(), num_alsa_fds, POLLIN);
 118                 fds[num_alsa_fds].fd = should_quit_fd;
 119                 fds[num_alsa_fds].events = POLLIN;
 120                 fds[num_alsa_fds].revents = 0;
 121
 122                 err = poll(fds.get(), num_alsa_fds + 1, -1);
 123                 if (err == 0 || (err == -1 && errno == EINTR)) {
 124                         continue;
 125                 }
 126                 if (err == -1) {
 127                         perror("poll");
 128                         break;
 129                 }
 130                 if (fds[num_alsa_fds].revents) {
 131                         // Activity on should_quit_fd.
 132                         break;
 133                 }
 134
 135                 // Seemingly we can get multiple events in a single poll,
 136                 // and if we don't handle them all, poll will _not_ alert us!
 137                 while (!should_quit) {
 138                         snd_seq_event_t *event;
 139                         err = snd_seq_event_input(seq, &event);
 140                         if (err < 0) {
 141                                 if (err == -EINTR) continue;
 142                                 if (err == -EAGAIN) break;
 143                                 fprintf(stderr, "snd_seq_event_input: %s\n", snd_strerror(err));
 144                                 return;
 145                         }
 146                         if (event) {
 147                                 handle_event(seq, event);
 148                         }
 149                 }
 150         }
 151 }
 152
 153 void MIDIMapper::handle_event(snd_seq_t *seq, snd_seq_event_t *event)
 154 {
 155         switch (event->type) {
 156         case SND_SEQ_EVENT_CONTROLLER: {
 157                 printf("Controller %d changed to %d\n", event->data.control.param, event->data.control.value);
 158
 159                 const int controller = event->data.control.param;
 160                 const float value = map_controller_to_float(event->data.control.value);
 161
 162                 // Global controllers.
 163                 match_controller(controller, MIDIMappingBusProto::kLocutFieldNumber, MIDIMappingProto::kLocutBankFieldNumber,
 164                         value, bind(&ControllerReceiver::set_locut, receiver, _2));
 165                 match_controller(controller, MIDIMappingBusProto::kLimiterThresholdFieldNumber, MIDIMappingProto::kLimiterThresholdBankFieldNumber,
 166                         value, bind(&ControllerReceiver::set_limiter_threshold, receiver, _2));
 167                 match_controller(controller, MIDIMappingBusProto::kMakeupGainFieldNumber, MIDIMappingProto::kMakeupGainBankFieldNumber,
 168                         value, bind(&ControllerReceiver::set_makeup_gain, receiver, _2));
 169
 170                 // Bus controllers.
 171                 match_controller(controller, MIDIMappingBusProto::kTrebleFieldNumber, MIDIMappingProto::kTrebleBankFieldNumber,
 172                         value, bind(&ControllerReceiver::set_treble, receiver, _1, _2));
 173                 match_controller(controller, MIDIMappingBusProto::kMidFieldNumber, MIDIMappingProto::kMidBankFieldNumber,
 174                         value, bind(&ControllerReceiver::set_mid, receiver, _1, _2));
 175                 match_controller(controller, MIDIMappingBusProto::kBassFieldNumber, MIDIMappingProto::kBassBankFieldNumber,
 176                         value, bind(&ControllerReceiver::set_bass, receiver, _1, _2));
 177                 match_controller(controller, MIDIMappingBusProto::kGainFieldNumber, MIDIMappingProto::kGainBankFieldNumber,
 178                         value, bind(&ControllerReceiver::set_gain, receiver, _1, _2));
 179                 match_controller(controller, MIDIMappingBusProto::kCompressorThresholdFieldNumber, MIDIMappingProto::kCompressorThresholdBankFieldNumber,
 180                         value, bind(&ControllerReceiver::set_compressor_threshold, receiver, _1, _2));
 181                 match_controller(controller, MIDIMappingBusProto::kFaderFieldNumber, MIDIMappingProto::kFaderBankFieldNumber,
 182                         value, bind(&ControllerReceiver::set_fader, receiver, _1, _2));
 183                 break;
 184         }
 185         case SND_SEQ_EVENT_NOTEON: {
 186                 const int note = event->data.note.note;
 187
 188                 printf("Note: %d\n", note);
 189
 190                 // Bank change commands. TODO: Highlight the bank change in the UI.
 191                 for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 192                         const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 193                         if (bus_mapping.has_prev_bank() &&
 194                             bus_mapping.prev_bank().note_number() == note) {
 195                                 current_controller_bank = (current_controller_bank + num_controller_banks - 1) % num_controller_banks;
 196                         }
 197                         if (bus_mapping.has_next_bank() &&
 198                             bus_mapping.next_bank().note_number() == note) {
 199                                 current_controller_bank = (current_controller_bank + 1) % num_controller_banks;
 200                         }
 201                         if (bus_mapping.has_select_bank_1() &&
 202                             bus_mapping.select_bank_1().note_number() == note) {
 203                                 current_controller_bank = 0;
 204                         }
 205                         if (bus_mapping.has_select_bank_2() &&
 206                             bus_mapping.select_bank_2().note_number() == note &&
 207                             num_controller_banks >= 2) {
 208                                 current_controller_bank = 1;
 209                         }
 210                         if (bus_mapping.has_select_bank_3() &&
 211                             bus_mapping.select_bank_3().note_number() == note &&
 212                             num_controller_banks >= 3) {
 213                                 current_controller_bank = 2;
 214                         }
 215                         if (bus_mapping.has_select_bank_4() &&
 216                             bus_mapping.select_bank_4().note_number() == note &&
 217                             num_controller_banks >= 4) {
 218                                 current_controller_bank = 3;
 219                         }
 220                         if (bus_mapping.has_select_bank_5() &&
 221                             bus_mapping.select_bank_5().note_number() == note &&
 222                             num_controller_banks >= 5) {
 223                                 current_controller_bank = 4;
 224                         }
 225                 }
 226
 227                 match_button(note, MIDIMappingBusProto::kToggleLocutFieldNumber, MIDIMappingProto::kToggleLocutBankFieldNumber,
 228                         bind(&ControllerReceiver::toggle_locut, receiver, _1));
 229                 match_button(note, MIDIMappingBusProto::kToggleAutoGainStagingFieldNumber, MIDIMappingProto::kToggleAutoGainStagingBankFieldNumber,
 230                         bind(&ControllerReceiver::toggle_auto_gain_staging, receiver, _1));
 231                 match_button(note, MIDIMappingBusProto::kToggleCompressorFieldNumber, MIDIMappingProto::kToggleCompressorBankFieldNumber,
 232                         bind(&ControllerReceiver::toggle_compressor, receiver, _1));
 233                 match_button(note, MIDIMappingBusProto::kClearPeakFieldNumber, MIDIMappingProto::kClearPeakBankFieldNumber,
 234                         bind(&ControllerReceiver::clear_peak, receiver, _1));
 235         }
 236         case SND_SEQ_EVENT_NOTEOFF:
 237                 // Ignore.
 238                 break;
 239         default:
 240                 printf("Ignoring MIDI event of unknown type %d.\n", event->type);
 241         }
 242 }
 243
 244 void MIDIMapper::match_controller(int controller, int field_number, int bank_field_number, float value, function<void(unsigned, float)> func)
 245 {
 246         if (bank_mismatch(bank_field_number)) {
 247                 return;
 248         }
 249
 250         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 251                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 252
 253                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 254                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 255                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 256                         continue;
 257                 }
 258                 const MIDIControllerProto &controller_proto =
 259                         static_cast<const MIDIControllerProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 260                 if (controller_proto.controller_number() == controller) {
 261                         func(bus_idx, value);
 262                 }
 263         }
 264 }
 265
 266 void MIDIMapper::match_button(int note, int field_number, int bank_field_number, function<void(unsigned)> func)
 267 {
 268         if (bank_mismatch(bank_field_number)) {
 269                 return;
 270         }
 271
 272         for (size_t bus_idx = 0; bus_idx < size_t(mapping_proto->bus_mapping_size()); ++bus_idx) {
 273                 const MIDIMappingBusProto &bus_mapping = mapping_proto->bus_mapping(bus_idx);
 274
 275                 const FieldDescriptor *descriptor = bus_mapping.GetDescriptor()->FindFieldByNumber(field_number);
 276                 const Reflection *bus_reflection = bus_mapping.GetReflection();
 277                 if (!bus_reflection->HasField(bus_mapping, descriptor)) {
 278                         continue;
 279                 }
 280                 const MIDIButtonProto &button_proto =
 281                         static_cast<const MIDIButtonProto &>(bus_reflection->GetMessage(bus_mapping, descriptor));
 282                 if (button_proto.note_number() == note) {
 283                         func(bus_idx);
 284                 }
 285         }
 286 }
 287
 288 bool MIDIMapper::bank_mismatch(int bank_field_number)
 289 {
 290         const FieldDescriptor *bank_descriptor = mapping_proto->GetDescriptor()->FindFieldByNumber(bank_field_number);
 291         const Reflection *reflection = mapping_proto->GetReflection();
 292         return (reflection->HasField(*mapping_proto, bank_descriptor) &&
 293                 reflection->GetInt32(*mapping_proto, bank_descriptor) != current_controller_bank);
 294 }